Macro-channel laser capable of being used for monitoring emergent light energy and preparation method of macro-channel laser

Abstract

The invention relates to the technical field of semiconductor laser, and discloses a macro-channel laser capable of being used for monitoring emergent light energy and a preparation method of the macro-channel laser. The laser comprises a laser chip, a WCu electrode, an A < l > N substrate and a water-cooling heat sink. The system is characterized by further comprising a set of light-emitting energy monitoring system, a light guide rod arranged near the light-emitting end of the chip collects scattered light, and a detector module at the tail end of the light guide rod converts light signals into electric signals in linear relation with light-emitting energy. The light guide rod can be formed by two groups of vertically butted light guide rods to twist a light path. In the preparation method, the step of packaging the chip to the WCu electrode and the step of packaging the semi-finished product to the heat sink adopt the same reflow soldering process parameters. According to the invention, the technical problem that a high-power laser lacks an integrated real-time energy monitoring scheme is solved, in-situ monitoring without influencing a main optical path is realized, and the heat dissipation performance and the working stability of the device are improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser technology, specifically to a macrochannel laser that can be used for monitoring emitted light energy and its fabrication method. Background Technology

[0002] Semiconductor lasers, especially macrochannel water-cooled vertical array lasers, are increasingly used in high-power-density applications such as laser medicine and materials processing due to their compact structure and high conversion efficiency. As their output power continues to increase, precise control and real-time monitoring of the laser's output energy are prerequisites for ensuring the safety and effectiveness of these applications.

[0003] However, current methods for monitoring the output energy of high-power lasers typically rely on external, non-integrated measurement devices. These methods cannot provide real-time energy feedback during laser operation, and their measurement operations interrupt the normal operation of the laser. While there have been attempts to integrate monitoring modules, these solutions often face difficulties in structural layout. The introduction of monitoring components increases the size and structural complexity of the overall laser module, limiting its application in devices with strict space constraints.

[0004] Furthermore, high-power lasers generate a significant amount of waste heat during operation, and their long-term stability and reliability are highly dependent on the thermal management performance of the packaging structure. In the heat conduction path from the laser chip to the macrochannel water-cooled heat sink, excessively high thermal resistance at any packaging interface will lead to a sharp increase in the chip junction temperature, thereby affecting the stability of its output power and its lifespan. In existing packaging processes, inconsistent process parameters in multi-step soldering processes can easily introduce differences in thermal resistance and accumulated stress between different solder layers, posing a technical challenge to ensuring the consistency and low thermal resistance of the overall heat dissipation path. Summary of the Invention

[0005] The technical problem this invention aims to solve is that existing macrochannel lasers, especially under high-power operation, lack a monitoring scheme that is highly integrated, does not affect the main optical path, and can reflect changes in optical energy in real time. Meanwhile, thermal management and process consistency during laser packaging are key technical challenges in ensuring long-term operational stability and reliability.

[0006] The first aspect of the present invention provides a macrochannel laser that can be used for monitoring emitted light energy, the macrochannel laser comprising: a laser chip; a WCu electrode; an AlN substrate; a macrochannel water-cooled heat sink; and positive and negative electrodes.

[0007] The WCu electrode is encapsulated on the AlN substrate via a gold-tin solder layer, and the laser chip is encapsulated on top of the WCu electrode. The AlN substrate is encapsulated on the macrochannel water-cooled heat sink. The positive and negative electrodes are disposed on the AlN substrate for external power supply. This structure forms an efficient heat conduction path from the laser chip to the macrochannel water-cooled heat sink.

[0008] As a core technical solution of the present invention, the macrochannel laser also includes an output energy monitoring system. The output energy monitoring system includes: at least one light guide rod, a detector module, and leads electrically connected to the detector module.

[0009] The light guide rod is positioned near the light-emitting end of the laser chip, and its function is to collect the scattered light generated when the laser chip emits light. The two ends of the light guide rod have parallel inclined sections of 0-90°, which is beneficial for the coupling and transmission of light.

[0010] The detector module is located at the end of the light guide rod and is used to receive the scattered light transmitted through the light guide rod and convert the optical signal of the scattered light into an electrical signal.

[0011] In one specific embodiment, the light guide rods consist of two sets: a first set and a second set. The first set of light guide rods is positioned perpendicular to the light emission direction of the laser chip, with its two ends having a parallel first tilt angle. The second set of light guide rods has the same number as the first set and is positioned perpendicular to the first set, with its two ends having a parallel second tilt angle. One tilted section of the first set of light guide rods and one tilted section of the second set of light guide rods are joined together by splicing or adhesive to achieve a 90° twist in the optical path. This compact structure facilitates guiding the optical signal to a suitable location for detection.

[0012] Regarding the material selection, the WCu electrode is a W-Cu alloy, wherein the weight percentage content of W is 70-90 wt%. The gold-tin solder layer is an Au-Sn alloy, wherein the weight percentage content of Au is 80 wt%.

[0013] In the specific implementation of the detector module, the detector module is a silicon-based photodiode. The silicon-based photodiode receives scattered light and converts it into a photocurrent signal, the magnitude of which is linearly related to the emitted light energy of the laser chip.

[0014] In terms of quantity configuration, the number of light guide rods is 0-1000, the number of detector modules is 0-1000, and the number of leads is 0-1000, with the number of leads corresponding to the number of detector modules.

[0015] A second aspect of the present invention provides a method for fabricating a macrochannel laser that can be used for monitoring emitted light energy, the method comprising the following steps:

[0016] S1. Component Pretreatment: The AlN substrate, WCu electrode, and laser chip are pretreated. The specific pretreatment operation is to ultrasonically clean the aforementioned components sequentially in acetone and isopropanol, and then dry them with high-purity nitrogen gas.

[0017] S2. Semi-finished product packaging: The AlN substrate pretreated in step S1, the WCu electrode pre-plated with a gold-tin solder layer with a thickness of 0-100 μm, and the laser chip are sequentially placed on a packaging fixture. Then, pressure blocks with a mass of 0-100 kg are applied to both ends of the AlN substrate, and a pressure block with a mass of 0-100 kg is applied to the WCu electrode. Finally, the entire fixture is sent into a reflow oven or heating table for packaging to obtain a semi-finished product.

[0018] S3. Overall packaging: The semi-finished product obtained in step S2 is placed on a macrochannel water-cooled heat sink. Positive and negative electrodes are added to the positive and negative poles of the semi-finished product, and a pressure block with a mass of 0-100kg is uniformly applied. Then, it is welded through a reflow oven or heating table to obtain the laser body.

[0019] S4. Energy monitoring system integration: Near the laser chip output end of the laser body obtained in step S3, a light guide rod is installed, and a corresponding detector module is installed at the end of the light guide rod. Finally, leads are welded to the detector module to obtain the macrochannel laser that can be used for light output energy monitoring.

[0020] To ensure consistent welding quality and process, both the encapsulation in step S2 and the welding in step S3 are performed in a reflow oven, and the encapsulation and welding use the same process parameters. These process parameters include: first, evacuation followed by filling with high-purity nitrogen as a protective atmosphere; then, a programmed temperature rise from room temperature to 150°C at a rate of 5-10°C / s, held for 60s; next, the temperature is raised to 250°C at a rate of 2-5°C / s, held for 60-90s; then, the temperature is raised to a peak temperature of 310-340°C and held for 30-60s; finally, cooling is performed at a rate of 5-10°C / s.

[0021] In a preferred embodiment, step S4, which involves installing the light guide rods and welding the leads, specifically comprises: first, installing the first set of light guide rods; then, installing the second set of light guide rods in a direction perpendicular to the first set of light guide rods; and finally, splicing or bonding the inclined sections of the two sets of light guide rods together using optical epoxy adhesive. Furthermore, the welding of the leads is performed using an ultrasonic gold wire ball welder.

[0022] To ensure optical performance, the refractive index of the optical epoxy adhesive matches that of the light guide rod, and the adhesive is cured by ultraviolet light after bonding.

[0023] To ensure the reliability of the electrical connection, gold wire with a diameter of 25-50 μm is used in the welding lead step.

[0024] This invention provides a macrochannel laser for monitoring emitted light energy and its fabrication method. It offers the following advantages:

[0025] 1. This invention achieves real-time, in-situ monitoring of the laser's output energy by placing a light guide rod near the laser chip's output end to collect the scattered light generated during emission. The optical signal is then converted into an electrical signal by a detector module at the end of the laser chip. Since the components of this monitoring scheme do not enter the optical path of the main emitted beam, they do not affect the energy or beam quality of the main beam.

[0026] 2. In the light emission energy monitoring system of the present invention, the light guide rod consists of a first set of light guide rods and a second set of light guide rods arranged perpendicularly to each other. The inclined cross-sections of the two sets of light guide rods are joined together to achieve a 90° twist of the optical path. This structure allows the detector module to be placed at a predetermined position outside the light emission axis, reducing the overall spatial size of the laser module and improving the system integration.

[0027] 3. In the preparation method of the present invention, the S2 step of packaging the laser chip to the WCu electrode and the S3 step of packaging the semi-finished product to the macrochannel water-cooled heat sink use the same reflow soldering process parameters, which include specific heating rate, holding time and peak temperature. This ensures that the heat conduction path from the laser chip to the macrochannel water-cooled heat sink is composed of a gold-tin solder layer with consistent process, thereby improving the heat dissipation performance and working stability of the device. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the semi-finished product packaging of AlN with WCu electrodes welded to the chip in Embodiment 1 of the present invention;

[0029] Figure 2 This is an exploded view of the semi-finished product packaged in Embodiment 1 of the present invention, in which WCu electrodes are welded to a chip on AlN.

[0030] Figure 3 The high-power macrochannel laser prepared in Embodiment 1 of the present invention;

[0031] Figure 4 In Embodiment 1 of the present invention, a light guide rod and a detector module are added to a high-power macrochannel laser;

[0032] Figure 5 This is a structural diagram of the detector module in Embodiment 2 of the present invention;

[0033] Figure 6 The response curves of the detector module for different wavelengths in Embodiment 2 of the present invention are shown.

[0034] Figure 7 This is a schematic diagram of the diffuse laser light generated after the laser reaches the object in Embodiment 2 of the present invention;

[0035] Figure 8 This is a schematic diagram of the laser chip of the present invention.

[0036] Among them, 1. Laser chip; 2. WCu electrode; 3. AlN substrate; 4. Detector module; 5. Light guide rod; 51. First group of light guide rods; 52. Second group of light guide rods; 6. Laser body; 7. Macrochannel laser for monitoring light output energy. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Examples 1-3:

[0039] Example 1:

[0040] This embodiment provides a macrochannel laser that can be used for monitoring emitted light energy and its fabrication method.

[0041] S1. Component Pretreatment: The AlN substrate 3, WCu electrode 2, and laser chip 1 are sequentially placed in acetone and isopropanol solvents for ultrasonic cleaning, with each solvent lasting 10 minutes. After cleaning, each component is dried using high-purity nitrogen gas for later use.

[0042] S2, Semi-finished product packaging reference Figure 1 and Figure 2Using a packaging fixture, the AlN substrate 3, pretreated in step S1, is first placed in a predetermined position. Then, a WCu electrode 2, pre-plated with a 10μm thick gold-tin solder layer, and a laser chip 1 are sequentially placed on the surface of the AlN substrate 3. (See attached image.) Figure 8 A 0.02 kg weight was applied to both ends of the AlN substrate 3, and a 0.06 kg weight was applied to the WCu electrode 2.

[0043] The entire fixture equipped with the above components is placed into a reflow oven, evacuated, and then filled with high-purity nitrogen as a protective atmosphere. It is then packaged according to the following process parameters:

[0044] The temperature was increased from room temperature to 150°C at a rate of 5°C / s and held for 60 seconds.

[0045] The temperature is then increased to 250℃ at a rate of 2℃ / s and held for 60s.

[0046] Then raise the temperature to the peak temperature of 310℃ and hold for 30 seconds;

[0047] Finally, the material is cooled at a rate of 5°C / s. After cooling, a semi-finished product is obtained with WCu electrodes 2 and laser chip 1 soldered onto the AlN substrate 3.

[0048] S3, Overall Package Reference Figure 3 The semi-finished product obtained in step S2 is placed on a macrochannel water-cooled heat sink, and positive and negative electrodes are added to the positive and negative positions of the semi-finished product. Then, a 0.06 kg weight is uniformly applied to the entire assembly, and the assembly is sent to a reflow oven for welding. The welding process parameters are exactly the same as the packaging process parameters in step S2. After welding and cooling, the laser body 6 is obtained.

[0049] S4, Energy Monitoring System Integration Reference Figure 4 In step S3, an energy monitoring system is integrated near the light-emitting end of the laser chip 1 of the laser body 6. First, a first set of light guide rods 51, with parallel 30° inclined sections at both ends, is installed perpendicular to the light-emitting direction of the laser chip 1. Next, a second set of light guide rods 52, with parallel 60° inclined sections at both ends, is installed perpendicular to the first set of light guide rods 51. Using an optical epoxy adhesive with a refractive index matching that of the light guide rods 5, the inclined sections of the two light guide rods are joined together to achieve a 90° twist in the optical path, and then cured using ultraviolet light. A detector module 4 is installed at the end of the second set of light guide rods 52. Finally, using an ultrasonic gold wire ball welder and a 25μm diameter gold wire, a lead is welded to the electrode of the detector module 4, thus obtaining the macrochannel laser 7 of this embodiment that can be used for light emission energy monitoring.

[0050] Example 2:

[0051] This embodiment provides a macrochannel laser that can be used for monitoring emitted light energy and its fabrication method.

[0052] S1. The component pretreatment is the same as in Example 1, and the AlN substrate 3, WCu electrode 2 and laser chip 1 are pretreated.

[0053] S2. Semi-finished product packaging: Using a packaging fixture, the AlN substrate 3, which has undergone pretreatment in step S1, is first placed in a predetermined position. Then, a WCu electrode 2, pre-plated with a 50μm thick gold-tin solder layer, and a laser chip 1 are sequentially placed on the surface of the AlN substrate 3. Pressure blocks weighing 50kg are applied to both ends of the AlN substrate 3, and a pressure block weighing 50kg is also applied to the WCu electrode 2.

[0054] The entire fixture equipped with the above components is placed into a reflow oven, evacuated, and then filled with high-purity nitrogen as a protective atmosphere. It is then packaged according to the following process parameters:

[0055] The temperature was increased from room temperature to 150°C at a rate of 7.5°C / s and held for 60 seconds.

[0056] The temperature is then increased to 250℃ at a rate of 3.5℃ / s and held for 75 seconds.

[0057] Then raise the temperature to the peak temperature of 325℃ and hold for 45 seconds;

[0058] Finally, the product is cooled at a rate of 7.5℃ / s. After cooling, a semi-finished product is obtained.

[0059] S3. Overall Packaging: The semi-finished product obtained in step S2 is placed on a macrochannel water-cooled heat sink, and positive and negative electrodes are added to the positive and negative positions of the semi-finished product. Then, a 50kg weight is uniformly applied to the entire assembly, and the assembly is sent to a reflow oven for welding. The welding process parameters are exactly the same as the packaging process parameters in step S2. After welding and cooling, the laser body 6 is obtained.

[0060] S4. The energy monitoring system is integrated near the light-emitting end of the laser chip 1 in the laser body 6 obtained in step S3. First, two first-set light guide rods 51 are installed perpendicular to the light-emitting direction of the laser chip 1, with parallel 60° inclined sections at both ends. Second, two second-set light guide rods 52 are installed perpendicular to the first-set light guide rods 51, with parallel 30° inclined sections at both ends. Using an optical epoxy adhesive with a refractive index matching that of the light guide rods 5, the inclined sections of the two sets of light guide rods are glued together to achieve a 90° twist in the optical path, and then cured by ultraviolet light.

[0061] Two detector modules 4 are installed at the ends of the second set of light guide rods 52. (Refer to...) Figure 5 The detector module is marked with an Index Marking, used for installation and positioning to ensure precise alignment with the end of the light guide rod; it is marked with a Cathode, one of the detector's electrodes, used for electrical signal transmission; it is marked with an Anode, the other electrode of the detector, which works with the cathode to achieve electrical signal input and output, supporting the transmission of the detection signal; and it is marked with a Photosensitive Area, the core functional area of ​​the detector, used to receive the laser (reflected light or scattered light) transmitted through the light guide rod, realizing the conversion of "optical signal → electrical signal".

[0062] Detector module 4 has index marks for installation and positioning, an anode, a cathode, and a photosensitive area measuring 1.1 mm × 1.1 mm. The responsivity characteristics of detector module 4 to different wavelengths of laser light are shown in reference... Figure 6 , refer to Figure 6 The horizontal axis (X-axis) is labeled Wavelength (nm), representing the laser wavelength, with a value ranging from 300nm to 1100nm, covering the wavelength range of common high-power lasers; (Refer to...) Figure 6 The vertical axis (Y-axis) is labeled Photosensitivity (A / W), representing the detector's photosensitivity (a responsivity-related parameter reflecting the ability to convert light signals into electrical signals). Its value ranges from 0.0 to 0.6 A / W; a higher value indicates a more sensitive response to the corresponding wavelength. The curve trend is as follows: the curve starts at approximately 300 nm wavelength and a photosensitivity of approximately 0.1 A / W, gradually increasing with wavelength, reaching a peak in the 700 nm-800 nm range (the peak value is close to 0.5 A / W). Afterward, as the wavelength continues to increase, the photosensitivity decreases, dropping to near 0 A / W around 1100 nm. The monitoring signal originates from the scattered light generated on the surface of the object after the laser beam is emitted, and the principle is described in [reference needed]. Figure 7 Finally, using an ultrasonic gold wire ball soldering machine and gold wire with a diameter of 38μm, the two leads were soldered to the electrodes of the two detector modules 4 respectively, thus obtaining the macrochannel laser 7 of this embodiment that can be used for light emission energy monitoring.

[0063] Example 3:

[0064] This embodiment provides a macrochannel laser that can be used for monitoring emitted light energy and its fabrication method.

[0065] S1. The component pretreatment is the same as in Example 1, and the AlN substrate 3, WCu electrode 2 and laser chip 1 are pretreated.

[0066] S2. Semi-finished product packaging: Using a packaging fixture, the AlN substrate 3, which has undergone pretreatment in step S1, is first placed in a predetermined position. Then, a WCu electrode 2, pre-plated with a 100μm thick gold-tin solder layer, and a laser chip 1 are sequentially placed on the surface of the AlN substrate 3. A 100kg weight is applied to both ends of the AlN substrate 3, and a 100kg weight is also applied to the WCu electrode 2.

[0067] The entire fixture equipped with the above components is placed into a reflow oven, evacuated, and then filled with high-purity nitrogen as a protective atmosphere. It is then packaged according to the following process parameters:

[0068] The temperature was increased from room temperature to 150°C at a rate of 10°C / s and held for 60 seconds.

[0069] The temperature is then increased to 250℃ at a rate of 5℃ / s and held for 90s.

[0070] Then raise the temperature to the peak temperature of 340℃ and hold for 60 seconds;

[0071] Finally, the product is cooled at a rate of 10℃ / s. After cooling, a semi-finished product is obtained.

[0072] S3. Overall Packaging: The semi-finished product obtained in step S2 is placed on a macrochannel water-cooled heat sink, and positive and negative electrodes are added to the positive and negative positions of the semi-finished product. Then, a 100kg weight is uniformly applied to the entire assembly, and the assembly is sent to a reflow oven for welding. The welding process parameters are exactly the same as the packaging process parameters in step S2. After welding and cooling, the laser body 6 is obtained.

[0073] S4. The energy monitoring system is integrated near the light-emitting end of the laser chip 1 in the laser body 6 obtained in step S3. First, 1000 first-group light guide rods 51 are installed perpendicular to the light-emitting direction of the laser chip 1, with parallel 45° inclined sections at both ends. Second, 1000 second-group light guide rods 52 are installed perpendicular to the first-group light guide rods 51, with parallel 45° inclined sections at both ends. Using an optical epoxy adhesive with a refractive index matching that of the light guide rods 5, the inclined sections of the two groups of light guide rods are glued together to achieve a 90° twist in the optical path, and then cured by ultraviolet light. 1000 detector modules 4 are installed at the end of the second-group light guide rods 52. Finally, using an ultrasonic gold wire ball soldering machine and gold wire with a diameter of 50μm, 1000 leads are soldered to the electrodes of the 1000 detector modules 4, respectively, to obtain the macrochannel laser 7 of this embodiment that can be used for light emission energy monitoring.

[0074] Comparative Examples 1-2:

[0075] Comparative Example 1:

[0076] Compared to Example 2, the difference is that the preparation in this comparative example ends after completing step S3, and the energy monitoring system integration in step S4 is not performed. That is, the light guide rod 5, detector module 4, and leads are not installed, and a macrochannel laser 7 without light output energy monitoring function is finally obtained. The remaining steps and parameters used are the same as in Example 2.

[0077] Comparative Example 2:

[0078] Compared to Example 2, the difference lies in the reflow soldering process parameters used for the semi-finished product packaging in step S2 and the overall packaging in step S3. Specifically, the process parameters for step S2 are exactly the same as in Example 2, while the soldering process parameters used in step S3 are: peak temperature 280°C and dwell time 20s. The remaining steps and parameters are the same as in Example 2.

[0079] Test Example 1-2:

[0080] Test Example 1: Light Emission Energy Monitoring Experiment

[0081] To verify whether the macrochannel laser 7 provided in this embodiment of the invention has the function of monitoring emitted light energy, and to verify the correspondence between its monitoring signal and the actual emitted light energy, this test is conducted.

[0082] The test objects are the macrochannel lasers 7 prepared in Examples 1, 2, and 3, and Comparative Example 1.

[0083] The testing equipment includes a tunable DC laser power supply, a macrochannel water chiller, a standard semiconductor laser power meter, a microammeter, a spectrum analyzer, and a light target.

[0084] Test steps:

[0085] The test object (e.g., the laser prepared in Example 1) is fixed on the test platform, and its macrochannel water-cooled heat sink is connected to the circulating water circuit of the water chiller.

[0086] Connect the positive and negative electrodes of the test object to the DC laser power supply. Connect the leads of the light output energy monitoring system of the test object to a microammeter.

[0087] A standard semiconductor laser power meter and a target are placed sequentially along the main beam exit path of the test object.

[0088] Start the water chiller and set the cooling water temperature to 25℃.

[0089] Turn on the DC laser power supply and set the drive current to the initial value of 20A. After the laser output stabilizes, record the readings of the standard semiconductor laser power meter (unit: W) and the microammeter (unit: μA).

[0090] Increment the drive current in steps of 20A and repeat step 5 until the drive current reaches 100A.

[0091] Turn off the laser power supply, replace the lasers used in Example 2, Example 3 and Comparative Example 1 with the lasers used in the test, and repeat the previous steps in sequence.

[0092] All recorded data are organized as shown in Table 1 below.

[0093] Test data:

[0094] Table 1. Light emission energy monitoring test data of Examples 1-3 and Comparative Example 1

[0095]

[0096]

[0097] Results analysis:

[0098] As shown in Table 1, the photocurrent signal values ​​of the lasers prepared using Examples 1, 2, and 3 all increase with the increase of actual output power. However, Comparative Example 1, lacking an integrated optical energy monitoring system, could not acquire a photocurrent signal. These results demonstrate that the technical solution proposed in this invention can provide an electrical signal related to the actual output power of the laser.

[0099] The monitoring mechanism of this invention lies in the fact that during the operation of the laser chip 1, its light-emitting end face generates scattered light proportional to the energy of the main beam. A light guide rod 5, positioned near the light-emitting end of the chip, collects this scattered light and transmits it through total internal reflection. Through the orthogonal docking structure of the first set of light guide rods 51 and the second set of light guide rods 52, the optical path is twisted by 90°, ultimately guiding the optical signal to the photosensitive area of ​​the detector module 4.

[0100] Detector module 4 converts the received scattered light signal into a photocurrent signal. Since the collected scattered light energy has a fixed proportional relationship with the output energy of the main beam, the magnitude of the photocurrent signal output by detector module 4 can linearly reflect the change in the actual output power of the laser. Experimental data verified this linear correspondence, confirming that this integrated monitoring system can achieve real-time, in-situ characterization of the laser's output energy state without interfering with the main optical path.

[0101] Test Example 2: Device Operational Stability Test

[0102] To verify the impact of the preparation method of the present invention on the stability of device operation, and in particular to verify the technical effect of using the same process parameters in steps S2 and S3, this test was conducted.

[0103] The test subject is the macrochannel laser 7 prepared in Example 2 and Comparative Example 2.

[0104] The testing equipment includes a tunable DC laser power supply, a macrochannel water chiller, a standard semiconductor laser power meter, a high-precision thermal imager, and a timer.

[0105] Test steps:

[0106] The test object (e.g., the laser prepared in Example 2) is fixed on the test platform, and its macrochannel water-cooled heat sink is connected to the circulating water circuit of the water chiller.

[0107] Connect the positive and negative electrodes of the test object to a DC laser power supply. Focus the high-precision thermal imager on the area where the laser chip 1 of the test object is located to monitor its operating temperature.

[0108] A standard semiconductor laser power meter is placed in the main beam output path of the test object.

[0109] Start the water chiller and set the cooling water temperature to 25°C and keep it constant.

[0110] Turn on the DC laser power supply and set the drive current to 100A to enable the laser to operate continuously at its rated power.

[0111] At the start of the test (working time is 0h), the temperature of the chip area displayed by the thermal imager and the output power displayed by the power meter are recorded.

[0112] During a 100-hour continuous operation cycle of the laser, the chip area temperature and output power were recorded every 20 hours.

[0113] Turn off the laser power supply, replace the test object with the laser of Comparative Example 2, and repeat the previous steps under exactly the same conditions.

[0114] All recorded data are organized as shown in Table 2 below.

[0115] Test data:

[0116] Table 2. Operational stability test data of Example 2 and Comparative Example 2

[0117]

[0118]

[0119] Results analysis:

[0120] The experimental data in Table 2 clearly show that during 100 hours of continuous operation testing, the laser prepared in Example 2 had a maximum chip region temperature of 56.8°C, with stable overall temperature changes; its output power decreased from 99.5W to 97.2W, with a power attenuation rate of 2.31%. In contrast, the laser prepared in Comparative Example 2 showed that its chip region temperature continuously increased from 68.1°C to 75.8°C; its output power decreased from 99.3W to 91.5W, with a power attenuation rate of 7.85%.

[0121] The aforementioned performance differences are directly attributed to the consistency of the soldering process in the preparation method. In Example 2, the S2 semi-finished product packaging step and the S3 overall packaging step employed the exact same reflow soldering process parameters. This method ensures that the entire heat conduction path from the laser chip 1 through the WCu electrode 2, the AlN substrate 3, and finally to the macrochannel water-cooled heat sink is composed of a gold-tin solder layer with uniform process conditions. Uniform process parameters facilitate the formation of a solder layer with fewer interface defects and a dense structure, thereby constructing a continuous heat conduction path with low thermal resistance.

[0122] The low thermal resistance heat conduction path allows the waste heat generated during laser chip 1's operation to be rapidly conducted to the macrochannel water-cooled heat sink and carried away. As the experimental data shows, this enables the laser chip of Example 2 to maintain a lower operating temperature. The lower chip temperature slows down the aging rate of the material and thermal stress, thus the device exhibits less power decay and higher operational stability. In contrast, Comparative Example 2, due to its inconsistent soldering process, has a higher thermal resistance in the heat conduction path, resulting in reduced heat dissipation efficiency, increased chip temperature, and consequently accelerated power decay.

Claims

1. A macro-channel laser usable for outcoupled power monitoring, characterized in that, Comprising: a laser chip (1); a WCu electrode (2) encapsulated on an AlN substrate (3) by a gold-tin solder layer; an AlN substrate (3) on which the laser chip (1) is encapsulated above the WCu electrode (2); a macro-channel water-cooled heat sink on which the AlN substrate (3) is encapsulated; positive and negative electrodes provided on the AlN substrate (3) for external power supply; and an out-light energy monitoring system comprising: at least one light guide rod (5) provided near the light emitting end of the laser chip (1) for collecting scattered light generated by the light emitting of the laser chip (1), wherein both ends of the light guide rod (5) have parallel inclined sections with an angle of 0-90°; a detector module (4) provided at the end of the light guide rod (5) for receiving the scattered light transmitted through the light guide rod (5) and converting the scattered light into an electrical signal; and a lead wire electrically connected to the detector module (4).

2. A macro-channel laser usable for outcoupled power monitoring according to claim 1, characterized in that, The light guide rod (5) comprises: a first group of light guide rods (51) provided in a direction perpendicular to the light emitting direction of the laser chip (1), both ends of the first group of light guide rods (51) having parallel first inclined angles; a second group of light guide rods (52) having the same number as the first group of light guide rods (51) and provided in a direction perpendicular to the first group of light guide rods (51), both ends of the second group of light guide rods (52) having parallel second inclined angles; the end inclined section of the first group of light guide rods (51) is connected to the end inclined section of the second group of light guide rods (52) by splicing or gluing, completing a 90° twist of the light path.

3. The macro-channel laser for light output energy monitoring according to claim 1, wherein, The WCu electrode (2) is a W-Cu alloy, and the gold-tin solder layer is an Au-Sn alloy.

4. The macro-channel laser for light output energy monitoring of claim 1, wherein, The detector module (4) is a silicon-based photodiode for receiving the scattered light and converting the scattered light into a photocurrent signal in linear relationship with the out-light energy of the laser chip (1).

5. The macro-channel laser for out-coupled power monitoring of claim 1, wherein, The number of light guide rods (5) is 0-1000, the number of detector modules (4) is 0-1000, and the number of lead wires is 0-1000, corresponding to the number of detector modules (4).

6. A method for fabricating a macrochannel laser that can be used for monitoring emitted light energy, characterized in that, A macro-channel laser for out-light energy monitoring according to any one of claims 1-5, comprising the following steps: S1, component pretreatment: pretreat the AlN substrate (3), WCu electrode (2) and laser chip (1) by sequentially ultrasonic cleaning in acetone and isopropyl alcohol and blowing dry with high-purity nitrogen; S2, semi-finished product packaging: the AlN substrate (3) pre-processed in step S1, the WCu electrode (2) pre-plated with a gold-tin solder layer with a thickness of 0-100 μm, and the laser chip (1) are placed in sequence on a packaging jig; then a pressure block with a mass of 0-100 kg is applied to both ends of the AlN substrate (3), and a pressure block with a mass of 0-100 kg is applied to the top of the WCu electrode (2); finally, the whole assembly is sent to a reflow oven or a heating table for packaging, and a semi-finished product is obtained; S3, overall packaging: the semi-finished product obtained in step S2 is placed on a macro-channel water-cooled heat sink, positive and negative electrodes are added to the positive and negative electrodes of the semi-finished product, and a pressure block with a mass of 0-100 kg is uniformly applied, and welding is performed through a reflow oven or a heating table to obtain a laser main body (6); S4, energy monitoring system integration: a light guide rod (5) is installed near the light emitting end of the laser chip (1) of the laser main body obtained in step S3, and a corresponding detector module (4) is installed at the end of the light guide rod (5), and finally the lead wire is welded to the detector module (4) to obtain the macro-channel laser (7) which can be used for light emitting energy monitoring.

7. The method of claim 6, wherein the macro-channel laser is used for light energy monitoring. The packaging in step S2 and the welding in step S3 are both performed in a reflow oven, and the same process parameters are used for packaging and welding, including: After vacuumizing, high-purity nitrogen is filled as a protective atmosphere; the temperature is raised from room temperature to 150°C at a rate of 5-10°C / s, and the temperature is maintained for 60s; then the temperature is raised to 250°C at a rate of 2-5°C / s, and the temperature is maintained for 60-90s; Then the temperature is raised to a peak temperature of 310-340°C and maintained for 30-60s; finally, cooling is performed at a rate of 5-10°C / s.

8. The method of claim 6, wherein the macro-channel laser is used for light energy monitoring. In step S4, the steps of installing the light guide rod (5) and welding the lead wire are as follows: Install the first group of light guide rods (51); Then install the second group of light guide rods (52) in a direction perpendicular to the first group of light guide rods (51); The inclined sections of the two groups of light guide rods are spliced or adhesively connected by an optical epoxy adhesive; Moreover, the step of welding the lead wire is completed by an ultrasonic gold wire ball bonding machine.

9. The method of claim 8, wherein the macro-channel laser is used for light energy monitoring. The refractive index of the optical epoxy adhesive matches the refractive index of the light guide rod (5), and the adhesively connected part is cured by ultraviolet light.

10. The method of claim 8, wherein the macro-channel laser is used for light energy monitoring. In the step of welding the lead wire, a gold wire with a diameter of 25-50 μm is used.

Images